Well-drilling apparatus



Feb. 21, 1950 s. WRIGHT 2,498,192

- WELL DRILLING APPARATUS Filed Aug. 24, 1944 2 Sheets-Sheet 1 INVENTOR.

I BY m ATTORNEY.

Feb. 21, 1950 s. WRlGHT 2,498,192

WELL DRILL-ING APPARATUS Filed Aug. 24, 1944 2 Shets-Sheet 2 ATTORNEY.

L I 24 I6 *20 f8 6 /5 j l3 6 A /5 4 /6 i I /6 /5a /5a l Z6 Z4 F 25 25 /5 mf 1 BY Patented Feb. 21, 1950 I UNITED STATES QEFIQ WELL-DRILLING APrAna'rUs Stanley Wright, Long Beach: (lalif lassignor by direct and mes-ne assignmentato Eastman Oil Well Survey Company, l)alla's,"'liex;, and Den ver, (3010;, a corporation of'lielaware Application August 24, 1944; Serial N 0. 550,929

11 Claims.

This invention relates to new and useful improvements in well drilling apparatus.

One object of the invention is to provide an improved apparatus for drilling well bores at a desired angle and in a predetermined direction, whereby said apparatus is particularly useful in directional drilling, side-tracking and similar operations.

An important object of the invention is to provide an improved drillingapparatus for deflecting the course of a well bore, said apparatus being so constructed that the deflected portion of the bore may be drilled to full gauge or size without the necessity of performing a subsequent reaming operation with a separate reaming tool.

A further object of the invention is to provide animproved drilling apparatus including a guide subhaving means for guiding ordirecting the drill bit into the-formation at a desired angle with respect to the main well bore, said sub having substantially full gauge reaming cutters thereon .and being arranged to be connected with the drill stem after the pilot drilling operation has beenistarted, whereby'said sub is subsequently actuated by the drill stem "to ream the bore hole to fulligauge.

Still another object of the invention is to provide an apparatus, of the character described, wherein a guide and reaming sub is combined with a drill pipe having a drill bit mounted on its lower end, said sub being normally attached to the drill pipe bya detachable connection whereby'the' pipe, bit and'sub may be lowered and properly oriented within the well bore as a unit, after which the .bit and pipe may be detached from the subto perform a drilling operationwhich is guided by said sub; there being co-acting means on said drill pipe and said sub for reconnecting the parts to permit the sub to subsequently function as a reamer to ream the bore'formed by the bit to full gauge.

A particular object of the invention is to provide an improved apparatus, of the character de- SCIlbdfWhrBill .thedrillpipe extends through" the bore of the sub and also'wherein the drill bitis positioned within saidbore prior tothe beginning of the drilling operation; said sub hav-- ing its bore inclined with respect to the axis of the main well bore whereby as the drill bit moves downwardly through the bore, said bore acts to guide said bit into :the formation'at aprede'ter mined angle with respect to the mainwell' bore.

Still another object 'of the invention is to pro 1 vide an improved guide 'andreaming' sub having" an inclined-(guide bore-land:haiiing longitudinally:

extending reaming cutters on its exterior, said sub also having means for connecting said sub to the drill pipe extending through its borewherea by said pipe may be utilized to rotate saidsub to perform a reaming operation.

The construction designed to carry out the invention will be hereinafter described together with other features'of the invention.

The invention will be more readily understood from. a reading of a the following specification and by reierence'to the accompanying drawing,

wherein-an example of the invention is shown,

and wherein Figural is anelevation of animproveddr-illing apparatus, constructed in accordance with: the invention,.

Figure 2 is an enlarged view, partlyinsection and partly in elevation showing the drill pipe and bit attached to the guide sub prior tothe drilling operation,

Figure 3 is a view similar to Figure 2 and showing the connection between the drill pipe and sub after "a drilling operation has been carriedout,

Figure 14 is a transverse, vertical sectional view of the sub, with said'sub turned at a right angle with respect to .its position'as shown in Figures 2 and 3,

Figure 5 is a bottom view of said sub,

Figure 6' is :a' horizontal cross-sectionaliview; taken on the line 66 of Figure 4, and

Figure 7 is a :sectionaldetail"showinga modifled 'form'or iconnection' betweemthe drill stem and s'ubl In'the drawings 'the'numeral'lll designates adrill pipe or stemwhich 'hasadr'ill' bit H connected to its extreme lower end." A special cou-"- pling collar l2 (Figure 2) is connected "in the drill stem. I!) being spaced a "desired or prede "termined distance abovethe drill bit II by an elongate pipe section or drill collar l3." The coupling. i2 includes a downwardly extending shank M which is externallythreaded, while. the inner bore of the collar is formed with the usual threads "(not shown) for connection with the drilllpipe l 0 and the section It.v It is pointed out that the length'of the-sectioni3acontrols the distancebetween the externally threaded shank I4 of the coupling 12 and the drill bit II and by-varying.

the length of the section 13 this, spacing may be varied "in accordance .withyarious drilling condi-stions.

The r dri1l;i;stem: and tits associate I parts are adaptedi tame .conncntdultoaan uelongate.tubular sub l5. The sub I is clearly shown in Figures 2 to 4 and has its outer external surface cylindrical in cross-section. A plurality of longitudinally disposed reaming cutters it are preferably made integral with the body of the sub I5 and extend substantially throughout the length of the sub. As is clearly shown in Figure 5 the cutters 16 project radially from the body and are substantially equally spaced from each other around the external surface of the sub body. The extreme lower end of each cutter projects in a plane below the lower end [5a of the body and such lower end of each cutter is sharpened at H whereby when the sub is rotated within the formation said cutters will perform a reaming operation.

The body of the sub is provided with a longitudinally extending bore i8 and this bore is inclined with respect to the longitudinal axis of said body; this inclination is at a predetermined or desired angle and may be varied within the limits of the size of the body. The upper end of the inclined bore [8 is reduced to form a counterbore l9, whereby an internal annular shoulder 28 is formed within the sub. The upper portion of the counterbore i9 is formed with a threaded box 21 and the threads of this box are adapted to be engaged by the external threads which are formed on the shank M of the coupling l2, which coupling is mounted in the drill stem H). A pair of inclined circulation ports 22 are provided in the upper portion of the sub body and extend from the outer surface of the body to the counterbore 29 thereof. It is noted that the upper portion of the sub above the reaming cutters I6 is tapered or reduced toward the upper end of the box 2|.

In using the apparatus, the pipe section l3 extends through the counterbore l9 of the sub l5 and the drill bit H is disposed within the enlarged lower portion l8 of the bore. The coupling I2 is, of course, connected to the upper end of the section l3 and the drill pipe is, in turn, threaded into said coupling. A frangible shear pin 23 which is threaded through a radially extending opening 24 in the upper end of the sub has its inner end connected to the section l3, whereby the drill stem assembly and the sub are connected together. At such time the bit H is disposed wholly within the bore [8 of the sub.

The drill stem assembly having the sub attached thereto is lowered through the well bore A and upon reaching the lower end of said bore or in the case of side-tracking upon reaching the plug (not shown), the lower end of said sub is engaged with either the formation or the plug.

' The weight of the drill stem is then imposed upon the shear pin 23 to effect fracturing or" said pin and detachment of the drill stem assembly from the sub. When this occurs the drill stem and bit may be moved downwardly with respect to the sub and such downward movement is guided by the inclined bore l8 and counterbore I9. As previously pointed out the bore [8 and counterbore is are disposed at a predetermined angle with respect to the longitudinal axis of the sub body and therefore the drill bit is guided outwardly into the formation at an angle with respect to the axis of the main well bore A.

As the drill bit H moves outwardly from the sub the stem if! is rotated to rotate said bit and thereby perform the drilling of a pilot bore B. It is evident that the continued drilling is directed at an a ngle orinclination with respect to the main bore, since the section I3 is guided by the inclined counterbore it of the sub as said section continues to move downwardly there through. The drilling of the pilot bore B may continue to any desired or predetermined depth and this is controlled by the spacing between the bit H and the coupling 52 for obviously the drilling operation continues until the external threads on the shank M of the coupling l2 enter the threaded box 2i in the upper portion of the counterbore it of the sub. When this occurs the rotation of the drill stem makes up the connection between the threads of the shank Hi and the threads of the box 2!, whereby the drill stem is directly connected with the sub, as is clearly shown in Figure. 3.

By the time this connection between the drill stem and sub is made, the pilot bore B has been formed and a continued rotation of the drill stern will cause the drill stem assembly and the sub to rotate as a unit. The subsequent continued rotation of the stem will cause the rotation of the sub with the result that the cutters on it on the external surface of the said sub will perform a reaming operation. As is clearly illustrated the external diameter of the cutters is full-gauge or of the same size as the main well bore and thus the offset or inclined pilot bore B will be reamed out to full size. It is, of course, evident that as the drill stem is rotated to perform the reaming operation the drill bit 1 l is also rotated to continue drilling of the pilot bore B in advance of the reaming sub. During this drilling operation as well as during subsequent drilling and reaming operations, circulation of drilling fluid is permitted through the circulation ports 22 in the upper portion of the sub. Manifestly, the apparatus permits drilling of the offset or inclined pilot bore B to full size without removal of the apparatus and substitution of a separate reaming tool.

In side-tracking operations it is not ordinarily necessary to direct the pilot bore 13 in a desired or known compass direction with respect to the main well bore A; however, in controlled directional drilling it is desirable to locate the lower portion of the inclined bore 28 of the sub in a predetermined known position so that subsequent drilling will be in a desired direction. The present apparatus permits proper orientation of the sub 15 since said sub is initially connected to the drill pipe 10 by means of the shear pin 23. The orientation of said sub to locate its inclined bore 18 in a known position may be carried out either by the usual methods of drill pipe orientation or by well known methods of bottom hole orientation, such as disclosed in the patents to Miller, No. 2,327,658 or Hyer, No. 2,120,670. By properly orienting the sub prior to shearing of the pin 23 it is possible to carry out controlled directional drilling operations and to locate the offset bore B in a desired known compass direction. By varying the degree of inclination of the bore i8 and counterbore [9, the onset well bore B may be drilled at a desired angle with respect to the longitudinal axis of the main well bore A.

From the foregoing it will be seen that a very simple and efficient drilling apparatus is provided. The sub is initially connected with the drill pipe assembly by a frangible or other detachable means which permits said sub to be lowered with the drill stern and properly oriented within the hole if such orientation is desired.

After bottom is reached, the drill pipe is .dis-

connected from the sub and drilling of a .pilotnection between. the coupling l'z and the subli has been found satisfactory, any. suitable connecting means. may be provided for attaching these parts to eachotheni As an example, a plurality of spring-pressed pins25may be mounted in the shank I4 for engagement within recesses 26 formed in the. bore E9 of the sub (Figure 7) andthe invention is not to belimited to any particular connecting means. So long as the drill stem assembly may be reconnected with the subso that all of the parts operate as a unit the purposes of the inventioniwill be carried out.

Also, any suitable type of "drill bit may be employed. It ispointed out that since .thetdrillstem is reconnected-tothesub, said drillstem may be utilized to Withdraw the sub from the well bore after all operations are complete. It might occur that for some reason the threads on the shank become disconnected from the box at the upper end of the sub in which case the lifting of the drill stem would result in the drill bit H engaging the annular shoulder 28 within the sub and such engagement would result in the bit lifting said sub from the Well bore'as the drill stem is raised; Thus it "becomes apparent that with the. structure disclosed the removal of the .sub fromthe well bore is always assured.

The foregoing description of theinventionis explanatory thereof and *various changes iin the. size, shape and materials, as well as in the .de-v tails of the illustrated construction may be made, within the scope of the appended claims, without departing from the spirit of the invention.

What I claim and desire to secure by Letters Patent is:

1. A well drilling apparatus including, a drill pipe, a drill bit secured to the lower end of said pipe, an elongate tubular guide sub in axial alignment with the drill pipe and having a longitudinal bore through which the drill pipe and bit are movable, said sub being cylindrical and having its longitudinal bore inclined with respect to the longitudinal axis of said sub and of the drill pipe, means for detachably connecting the sub to the drill pipe with the bit disposed within the inclined bore of the sub to permit lowering of the pipe, bit and sub as a unit within the well bore, disconnection of the detachable means permitting movement of the drill pipe and stem relative to the sub, whereby the drill bit may be moved downwardly into the formation below said sub to drill a, pilot bore, the downward movement of the bit being at an angle with respect to the longitudinal axis of the sub and drill pipe, means for reconnecting the drill pipe with the sub after said drill pipe has moved a predetermined distance downwardly with respect to said sub, during the drilling of the pilot bore, and reaming means on the exterior of the sub so that subsequent rotation of the drill pipe after reconnection of said pipe and sub imparts rotation to the sub.

2. A well drilling apparatus including. a drill pi e, a drill bit secured to the lower end of said pipe, a guide and reaming sub having a, lon itudinal bore through which the drill pipe and bit: are -,movable,v means foridetachably; connect-,-- ing the subrtolthe drill spipe with the-bit-disposed-within thebore ofsaidsub to permit low-'- ering of the-pipe, bit andsubas a unitwi-thina': well bore, clisconnectionof the detachable means permitting movement ofzthe-drillpipe and stem relative to the sub whereby thedrill bit may be moved downwardly intostheformation below said sub=to-.drill-a pilot-bore,.co acting-means on the drill pipe and sub for effectinga :=fixed. connec-.

tion between.:these--parts after -the .pilot boreisdrilled whereby the sub may ,-be subsequentlyro tated with thepipe and bit; and reaming cutters on the exterior-of .thesub :for reamingthe'pilot bore to enlarge-thesame upon continued rotation of. the drill pipe, thefixed connection-maintaining the sub attached to the pipe during subse-e quent drilling l operations- 3. An apparatus as set-forth in claim 2, wherein the reaming cutters are substantially fullgauge so that the pilotbore is enlarged tothe same diameter as the main wellbore.

4. An apparatus as set forth in claim 2, where-:

in the sub is formed with circulation ports which extend-from the-hereof the sub to-=its-o .1-ter'sur. face for permitting circulationoi drillingefluidduringathe drillin'ggand reaming operations.

5.- As-a sub-combination in adrilling appara tus, a guide and reaming sub comprising a cylindr-ical-body, a:-lplurality-- of elongate reaming blades'on the exterior of -thebody, said subhaving-P a longitudinally extending bore within the bodywhich bore has its upper.end-counterbored' to a reduceddiameter witharespect' to *tl1eremainder of the'bore, the 'bore -'and'-. counterbore being disposed at an inclination with respect to the longitudinal axis 7 ofthe body 6. As. a sub-combination ina drilling anparatus including a support, a :guide. and. reaming sub comprising-a cylindrical body, apluralitv-ofelongate reaming blades on the exterior of the body, a longitudinally extending bore within the body having its upper end counterbored to a reduced diameter with respect to the remainder of the bore, the bore and counterbore being disposed at an inclination with respect to the longitudinal axis of the body, and connecting means within the counterbore for connecting the sub to the support of the apparatus in a position with the support extending through the bore of the sub and projecting from the lower end, thereof.

'7. A drilling apparatus as set forth in claim 2, wherein the co-acting-means for efiecting a fixed. connection is an internally threaded box at the up er end of the bore of the sub and an externallv threaded section on the drill pinev said externallv t readed section being spaced a predetermined distance above said box when the pipe isinitiallv detachably connected with the sub prior to t e dri ing o eration.

8. A well drilling apparatus including, a drill pipe, a drill bit secured to the lower end of said pipe, a guide sub having a longitudinal bore through which the drill pipe and bit are movable, means for detachably connecting the sub to the drill pipe with the bit disposed within the bore of said sub to permitlowering of the pipe, bit and sub as a unit within the well bore, disconnection of the detachable means permitting movement of the drill pipe and stem relative to the sub, whereby the drill bit may be moved downwardly into the formation below said sub to drill a pilot bore, co-acting means on the drill pipe and sub comprising spring-pressed elements mounted on the drill pipe and recesses formed in the sub in the upper portion thereof for connecting the pipe and sub together, the spring-pressed elements being disposed in spaced relation above the co-acting recesses in the sub when the sub is connected to the drill pipe by the detachable means and prior to a drilling operation, detachment of said detachable means and subsequent downward movement of the drill pipe and bit with relation to the sub to perform drilling of a pilot bore moving the spring-pressed elements carried by said drill pipe downwardly until said elements move opposite and engage the recesses in said sub, whereby the sub is coupled to the drill pipe and rotates therewith throughout subsequent drilling operations, and reaming cutters mounted on the external surface of the sub, whereby rotation of the sub following its connection to the drill pipe through the co-acting elements and recesses performs a reaming operation.

9. A well drilling apparatus including, a drill pipe, a drill bit mounted on the lower end of said pipe, an elongate guide and reaming sub through which the drill bit and pipe extend, said sub having a bore for guiding the drill bit and drill pipe as the same move downwardly therethrough whereby the drill bit at the lower end of said pipe is guided into the formation to drill a pilot bore, co-acting means on the drill pipe and on said sub adapted to be engaged with each other to connect these parts together when the bit and pipe have moved downwardly a predetermined distance with respect to the sub, whereby subsequent rotation of the drill pipe after such connection imparts rotation to the sub, and reaming blades on the exterior of the sub for reaming the well bore when said sub is rotated.

10. A well drilling apparatus as set forth in claim 9, together with frangible means for initially detachably fastening the drill pipe and sub together to permit lowering of the pipe, bit and sub as a unitary assembly, the connecting means on the drill pipe for effecting subsequent connection of the pipe and sub being spaced above the sub when the frangible means is fastening the parts together, whereby the frangible means must be broken and a predetermined downward movement of the pipe and bit with respect to the sub must be effected before said connecting means co-acts with means in the sub to rotatively couple the pipe and sub together.

11. A well drilling apparatus as set forth in claim 9, wherein the co-acting means for connecting the pipe and sub together is an internally threaded box at the upper end of the bore of the sub and an externally threaded section on the drill pipe, said externally threaded section being spaced a predetermined distance above said box when the drill bit is within the sub, whereby the bit and pipe must move downwardly a predetermined distance With respect to the sub in order to engage the external threaded sec tion and the box.

STANLEY WRIGHT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date Re. 20,405 Str0ud June 8, 1937 1,636,032 Abbott July 19, 1927 1,804,819 Spencer et al. May 12, 1931 2,065,896 Keever Dec. 29, 1936 2,101,185 Monroe Dec. 7, 1937 2,196,517 Bolton Apr. 9, 1940 2,323,027 Gerstenkorn June 29, 1943 2,345,766 Miller Apr. 4, 1944 

